August 1, 2022

expert reaction to perspective piece commenting on exploring catastrophic climate change scenarios

A perspective piece published in Proceedings of the National Academy of Sciences (PNAS) explores catastrophic climate change scenarios.

Prof Nigel Arnell, Professor of Climate Change Science, University of Reading, said:

“The authors of this perspective are broadly right: the possibility that climate change could lead to catastrophic consequences for human societies cannot be ignored and should inform climate policy, and it has been underemphasised in the research literature.  I think that there are rather more studies looking at high emissions scenarios than the authors of this ‘call to arms’ recognise – several global studies have used climate scenarios based on RCP8.5 emissions, for example – but I agree that these have tended to focus on direct impacts rather than the cascading risks that might wake up the ‘four horsemen’ that the authors warn us about.  In my view, the types of ‘integrated catastrophic assessments’ that the authors recommend are vital, and need to be based on a blend of quantitative analysis and expert judgment: there is enormous scope for sharing and learning between different research and assessment communities, and we really need to step up and do it.”

Dr Joeri Rogelj, Director of Research, Grantham Institute – Climate Change & Environment; and Reader in Climate Science & Policy, Centre for Environmental Policy, Imperial College London, said:

“We have to get serious about understanding the profound risks that come with moving our planet into unknown territory.  This piece doesn’t call for a doomist perspective.  It also doesn’t say we need more knowledge before we can act.  Instead, it calls for dedicated research efforts to understand how our societies would fare if we get seriously unlucky with how the climate responds to our emissions.  Researching these extreme cases means that we’ll be able to better prepare, including by being more serious about reducing emissions now.  Being a perspective piece this paper doesn’t provide any answers or new data yet; it simply tries to ensure that the research community doesn’t look past this important question.”

The Perspective piece, ‘Climate Endgame: Exploring catastrophic climate change scenarios’, by Luke Kemp et al. was published in PNAS at 20:00 UK time on Monday 1 August 2022.

DOI: 10.1073/pnas.2108146119

Declared interests

Prof Nigel Arnell: “No relevant interests: not involved in the original research.”

Dr Joeri Rogelj: “None.”